Smoke-controlled sprinkler



April 4, 1939. A, RATHWELL 2,152,973

y, SMOKECONTROLLED SPRINKLER Filed Jan. 1o, 195'8 Zivi/6177 OAL H. -7.` Raw/wsu Patented Apr. 4, 1939 UNITED STATES PATENT OFFICE Application January 10, 1938. Serial No. 184,158 In Canada. October 14, 1936 2 Claims.

This invention relates to smoke-controlled sprinklers.

The invention utilizes a photo-electric tube which is placed in the path of a beam of light; as the lumens impinging the tube decrease as a result of a body of smoke intersecting the beam, a relay operates to bring into play instrumentalities which govern the operation of the sprinkler. In order that the beam of light be lntersected as quickly as possible, to thus render the device sensitive, the smoke may be drawn by natural, but preferably by artical, means into a transparent tube positioned in the path of the beam of light. Preferably, the tube is bent upon itself to provide two or more smoke passages, or thicknesses of tube, all lying in a common plane, and disposed to lie in the path of the beam.

According to known practice, the modern sprinkler is temperature-controlled; that is, it is brought into play when temperature rises to a predetermined degree. Obviously, most sprinklers are set to operate at relatively high temperature, say, for instance, F. It often happens that before the temperature has risen to this point, a re has had time to gain considerable headway. If, on the other hand, the sprinkler is controlled by smoke, and not by temu perature, it will be brought into operation very quickly, as considerable smoke is in most cases generated as soon as combustion has started.

The objects of this invention, therefore, are to control a suitable device by a body oi smoke interposed between a photo-electric tube and a source of energizing light.

A specific object is to devise a smokeecontrolled sprinkler.

Another specific object is to render such a device exceedingly sensitive.

in the drawing, wherein like numerals of reference indicate corresponding parts in the various iigures,

Figure 1 is adiagrammatic representation of a sprinkler system operating in accordance with my invention;

Figure 2 is a fragmentary View of part of thev apparatus;

Figure 3 is a detail of the valve.

Referring now by numerals to the drawing, there is shown at A an enclosure, in the form of a room within which, or in association with which, is installed a suitable sprinkler system indicated generally by- B. The sprinkler may be fed by gravity from a tank C. The enclosure A may comprise a number of rooms communicating with one another, in the sense that smoke emanating from one room will readily diffuseor pass into the other room or rooms.

I0 is a photo-electric tubefand Il a source of light adapted to direct a beam of light upon the tube I0, all according to known practice. An amplifier may, if necessary, be associated with thetube, also according to known practice.

There is used a suitable relay i2, interposed in the circuit. which relay is controlled by the current passing through the tube. The current passing through the tube is controlled by the Y lumens impinging the tube. The lumens implng- `ing the tube are, in turn, controlled by any body intersecting or lying in the path of the beam of light from the source ii. in the present instance, the body of smoke intersecting or lying in the path of the beam of light, controls the lumens impinging the tube.

In order that the relay it may control the operation of the sprinkler, I may use a valve it, such as shown in Figun l, between the sprinkler proper and the source C of iiuid feeding the sprinkler.

l5 is the valve casing having an inlet it and an outlet Il. Within the casing is a plunger itl having a port l5 arranged therethrough, to allow the fluid to pass through the plunger when its port l5 is in register with the inlet and outlet i8 and il, respectively. The plunger has a rod 96A ares ranged to slide through the top and bottom walls of the casing, to act as a guiding member for the plunger. A spring imi is disposed between. the plunger and the bottom wall of the casing, which normally raises the plunger into operative position, that is a position to allow the iiuid to fio/w through the plunger. The rod projects above the top wall of the casing, as aforesaid. Piyot= ally mounted to the casing as at 2i, is a dog 22 which is operable to releasably lock the plunger in its lowered or inoperative position, (as shown in Figure 3), against the action of the spring 59A.. As the dog releases the rod, the plunger suddenly rises to its operative position, at which the huid passes from the source C to the sprinkler proper.

Between the dog 22 and a fixed point, is a spring 25 tensioned to swing the dog so as to release the rod. To the dog is secured an iron core or member 26 adapted to co-operate with the coil of the relay, which is wound to urge the core toward the rod. The tension in the spring, or the number of turns in the coil, is such that the dog is retained in its operative position, against the tension in the spring 25, until the current energizing the coil of the relay drops to a predetermined point, when the dog swings away from the rod to release the same.

If desired, the photo-electric tube I0 and light I I may be positioned within a separate enclosure A' closed from the enclosure A. Preferably, a transparent tube T is operatively connected at one end to the enclosure A and opens at the other end to the atmosphere. This tube is positioned to be in the path of the beam of light emitted from the light II.

Preferably also, there is used a suitable suction pump R, interposed in the length of the tube T, to draw air from the enclosure A. Any smoke generated within, or gaining access into the enclosure A, will be drawn into the tube T.

In order to render the device sensitive, the tube T may be formed as shown in Figure 2, that is, being bent upon itself to provide a plurality of continuous passages, or thicknesses of tube, all lying in a same plane, and all of which passages are in the path of the beam of light. In the particular form F shown in Figure 2, the device would be three times as sensitive as if a straight tube were used.

As will have been already gathered, any smoke drawn into the tube T will control the lumens impinging the photo-electric tube IIJ. The coil I2, controlling the valve I4, will be gradually deenergized as the density of the smoke increases,

until the electromotive force operating to hold the dog 22 in operative position will have decreased to a point where the dog will, under the action of the spring 25, swing away from the rod IBA to release the plunger or valve member I8. The sprinkler will now be brought into operation.

What I claim is:

l. In a smoke-responsive control, the combination of an enclosure, a photo-electric tube, a relay controlled by the current passing through said tube, a source oi' light adapted to direct a beam of light upon said tube, and a transparent tube operatively connected at one end to said enclosure to `receive smoke emanating therefrom and formed with a bent portion providing a plurality of thicknesses of tube in the path of the beam.

2. In a smoke-responsive control, the comblnatlon of an enclosure, a photo-electric tube, a relay controlled by the current passing through vsaid tube, a source of light adapted to direct a beam of light upon said tube, a transparent tube connected at one end to said enclosure to receive smoke therefrom, and means for drawing smoke into said transparent tube, said transparent tube having a portion bent to provide a plurality of thicknesses of tube in the path of the beam` ALBERT J. RA'I'HWELL. 

